Added Raphael to CODEOWNERS (#44)

Author: christian-kreuzberger-dtx

.github/CODEOWNERS

@@ -2,4 +2,4 @@
 # This file designates code owners for this repository.
 # Each line is a file pattern followed by one or more owners.
 
-* @christian-kreuzberger-dtx @krisdyna @MrManny
+* @christian-kreuzberger-dtx @krisdyna @MrManny @raphael-wigoutschnigg-dt